BOGOTA, Colombia (AP) _ President Ernesto Samper and his aides plotted to block the media, prosecutors and political opponents from looking into alleged drug corruption in his campaign, his former campaign chief testified.

The charges by Fernando Botero appeared in an accusation against the president that prosecutors presented to Congress last week and published in the respected El Tiempo newspaper on Friday.

Many of those whom Botero mentioned denied having been pressured.

Botero, the former defense minister jailed since August, broke months of silence in a Jan. 22 television appearance when he said Samper knowingly took millions of dollars from the Cali cocaine cartel.

In the charges published Friday, Botero said the president and a handful of ministers met at least 30 times after the 1994 election to discuss ways to cover-up the alleged payoffs.

He also accused Samper of trying to block efforts to capture the cartel leaders, though the government did put six of the seven drug kingpins behind bars last year.

Botero said the group discussed influencing judges to cut short the term of Prosecutor General Alfonso Valdivieso, who has led the probe into Samper's campaign.

They also plotted ``the use of official state apparatus, to intimidate people that could eventually testify against the government's interests'' and to find information damaging to potential enemies.

Botero said he, the president and the ministers of foreign relations, the interior and communications were at most of the meetings.

The group planned to use government control of new broadcast frequencies to gain favorable press coverage, and to influence a congressional commission investigating Samper by offering members lucrative deals, Botero said.

Enrique Santos Calderon, managing editor of El Tiempo, Colombia's largest newspaper, which is interested in developing new radio and TV stations, said the government never pressured his newspaper. Other media leaders also denied having been pressured.

The head of the congressional commission investigating Samper, Heyne Mogollon, and several judges whom Botero said were solicited also have denied being pressured by the president's circle.

Samper has denied knowing of drug money entering his campaign or taking part in a cover-up. The congressional commission is investigating him in proceedings that could lead to his impeachment.

The document that prosecutors gave the commission contains testimony from several other campaign aides, contributors and others.

Valdivieso, the prosecutor, said the president is ``seriously implicated'' in taking drug payoffs, exceeding campaign spending limits, electoral fraud and cover-up.

Botero and campaign treasurer Santiago Medina have testified that the campaign ran out of money and could not raise funds without help from the world's largest drug syndicate.

Former cartel accountant Guillermo Palomari, who is cooperating with U.S. drug agents, has backed up allegations that his bosses gave the campaign money.